Limnomedusa macroglossa has a snout vent length range of 37.6 - 55.0 millimeters, and a mass range of 7.3 - 20.5 grams (Kaefer et al. 2008). The body is stocky with long limbs and a head as wide as the body. The snout is blunt with the nostril closer to the tip than the eye. The canthus is distinct and the loreal region is slightly concave. The tympanum is very distinct being two-thirds the diameter of the eye. When the legs are adpressed to the body, the tibiotarsal articulation extends beyond the end of the snout. When the legs are placed at right angles to the body the heels overlap. The fingers and toes are slender and do not have disks. The first finger is longer than the second finger. The inner metatarsal tubercle is small and the outer is minute. Limnomedusa macriglossa has round glandular warts extending on either sides of the dorsal skin, but is smooth on the ventrum. There is a granular area on the outer surface of the thighs. The vomerine teeth are distinctly separated in conspicuous straight groups and are in line with the choanae. The tongue is round and flat (Schmidt 1944).

Limnomedusa macroglossa is grey on the dorsum with a bold pattern of darker brown spots; it is not clear whether this is in life or preservation. There is a conspicuous pair of canthal stripes that extend forward on the snout. The labial border is spotted and there is a large spot between the eyes along with and inverted "V" above the shoulders. Strong bars wrap the limbs. There is a large black nuptial pad on the base of the thumb with and isolated one on the lateral face of the inner metacarpal tubercle (Schmidt 1944).

Sexual dimorphism is present with females tending to be slightly larger in weight and snout-vent length than males, although this could be due to the fact that females were collected during their reproductive season (Kaefer et al. 2008).

Limnomedusa macroglossa can be found in northeastern Argentina (Misiones and Entre Rios) Uruguay, and southern Brazil (Paraná to Rio Grande do Sul) in rocky outcrops and stream beds (Kaefer et al. 2008). Limnomedusa macroglossa has an altitude range of 0 - 1,200 m and are mainly in open or forested areas near the rocky soil by rivers (Silvano et al. 2004).

Life History, Abundance, Activity, and Special Behaviors

Limnomedusa macroglossa has a reproductive season from late August to early February. They are recorded to be seen between 20 and 30 degrees Celsius (Kaefer et al. 2008).

During mating season males call form rocky points with their bodies half in the water. They mainly call under rocks but do occasionally call in open areas. Limnomedusa macriglossa amplexes in a semi-inguinal position (Kaefer et al. 2008).

Egg clutches were found mainly in isolated ponds over rocky ground. The eggs were almost circular with black on the animal pole and beige on the vegetative pole (Kaefer et al. 2008).

Tadpoles can be found in deforested areas in temporary ponds next to rivers (Silvano et al. 2004).

Trends and Threats

While L. macroglossa is listed as “Least Concern” for extinction there is some speculation that a river flooding could led to local extinction. Additionally, chemical or physical changes can have adverse effects on their reproductive behaviors, leading to a decline in population (Kaefer et al. 2008). Increased agriculture cultivation, water pollution, hydroelectric development, and pine plantations habitat degradation could also be threatening the species (Silvano et al. 2004).

Based off of sequences from the gene H1 and using heuristic tree searching methods along with heuristic homology assessments, Limnomedusa was resurrected as a genus and is sister to Odonotophrynini (Frost et al. 2006).

Since its description, Limnomedusa macroglossa has gone through multiple name changes. It was first described as Cystignathus macroglossus by Duméril and Bibron in 1841. The name was then changed to Rana (Limnomedusa) macroglossus in 1843 by Fitzinger. Cope first introduced its current name, Limnomedusa macroglossa, in 1866. However, in 1875, Jiménez de la Espada changed it to Litopleura maritimum and in 1936, Ahl renamed it Leptodactylus nova-teutoniae. In 1944, the name was changed by Schmidt to Limnomedusa misionis, but in 1971 Barrio synonymized this name with Limnomedusa macroglossa (Silvano et al. 2004, Frost 2017).

Frost, D.R. 2017. Limnomedusa macroglossa. Amphibian Species of the World: an Online Reference. Version 6.0. Electronic Database accessible accessible at http://research.amnh.org/herpetology/amphibia/index.html. American Museum of Natural History, New York, USA. Accessed on 7 November 2017.